Fugitive American Edward Snowden, who leaked details of secret surveillance operations in the UK and US, is expected to seek asylum in Ecuador.

The 30-year-old, who is wanted by the US on charges of espionage and theft of government property, arrived in Russia yesterday after boarding a flight from Hong Kong, where he has been in hiding.

The former British colony, now under Chinese rule, let the former US National Security Agency contractor leave the territory, despite Washington's efforts to extradite him to face espionage charges.

White House officials requested his extradition but he was allowed to leave because documents provided by the US did not "fully comply with the legal requirements under Hong Kong law," it was reported.

Ecuador's Foreign Minister, Ricardo Patino, wrote on Twitter: "The Government of Ecuador has received an asylum request from Edward J Snowden."

Whistleblowing group WikiLeaks announced Mr Snowden had requested legal help as he sought asylum in Ecuador.

The organisation's founder, Julian Assange, was granted asylum by the South American country last year after facing extradition to Sweden on sexual assualt charges, and has been staying at its embassy in London.

A statement released on the WikiLeaks website said: "Mr Edward Snowden, the American whistleblower who exposed evidence of a global surveillance regime conducted by US and UK intelligence agencies, has left Hong Kong legally.

"He is bound for the Republic of Ecuador via a safe route for the purposes of asylum, and is being escorted by diplomats and legal advisers from WikiLeaks.

"Mr Snowden requested WikiLeaks use its legal expertise and experience to secure his safety.

"Once Mr Snowden arrives in Ecuador, his request will be formally processed."

Former Spanish judge Baltasar Garzon, legal director of WikiLeaks and lawyer for Mr Assange, said: "The WikiLeaks legal team and I are interested in preserving Mr Snowden's rights and protecting him as a person.

"What is being done to Mr Snowden and to Mr Julian Assange – for making or facilitating disclosures in the public interest – is an assault against the people."

Mr Snowden's US passport has reportedly been revoked, while earlier reports sug- gested he might attempt to travel to Cuba and then on to Caracas, the Venezuelan capital.

He kept people guessing about his whereabouts and plans yesterday after leaving Hong Kong for Moscow, and stayed out of sight after the plane on which he was thought to be travelling landed at the Russian capital's Sheremetyevo airport.

A source at the Russian airline Aeroflot said Mr Snowden would fly to Cuba today and was expected to go on to Venezuela, despite Ecuador's claims.

Passengers arriving from Hong Kong said he may have been whisked away from the runway by waiting cars, initially prompting speculation he may spend the night in a foreign embassy in the Russian capital.

"There were a lot of police and black cars when we were getting off the plane," said one passenger.

Mr Snowden was reportedly seen at a hotel near the airport and Ecuador's ambassador to Russia, Patricio Alberto Chavez Zavala, spent several minutes inside the building.

The envoy told reporters as he arrived he expected to have talks with Mr Snowden and Sarah Harrison, a representative of the WikiLeaks anti-secrecy group.